A domain specific language for dynamic interest management within virtual environments

Abstract

Interest management is a widely used term within the area of virtual environments. It is so widely used that there even exist many synonyms for the concept. Thus both the terminology, and meaning of the concept are currently not well defined. The typical aim of interest management techniques within virtual environments has been to increase scalability. However, this thesis argues that the concept of interest management should not be so tightly coupled with the goal of scalable virtual environments, but be a concept in its own right, i.e. the management of interests. The main focus of this thesis is the representation of expressions of interest. The various techniques for expressing interest are surveyed and evaluated, providing the basis for the research into a suitable representation. This representation is achieved in two stages. The first part of this thesis introduces a novel dynamic interest management technique based upon set theory. It describes how it is expressive enough to implement most of the static interest management techniques currently available such as categorisation, locales, and interacting locales. By de-coupling the logic that implements these interests from the virtual environment, it can also describe how interests can be changed during the virtual environment's execution, thus making the technique dynamic. Enforcing and denying interests is also considered, allowing for the enforcement of interests integral to the requirements of the virtual environment. An example of this is denying the user the ability to be interested in artefacts that aren't visible. The new approach presented is implemented with SQL, and evaluated. The second part of this thesis focusses on the limitations of using SQL as an implementation language, focussing on issues of readability and succinctness and a lack of any abstraction mechanisms. Overcoming these limitations is treated as the primary design goal for a new domain specific language for representing interests. The thesis introduces this language, Wish, and evaluates it within the domain, demonstrating that it is as expressive as SQL yet is more readable, conceptually succinct and allows for arbitrary abstraction of complexity.